The last time the cast was assembled was 2003's American Wedding, which saw Biggs' Jim and Hannigan's Michelle get married. In an interview with Entertainment Weekly, Hannigan revealed what's in store for American Reunion.

We’ll, we’re still married, and we have a child. So we’re navigating the waters of parenthood and how that changes the dynamics of a relationship. But also they’re going back to their high school reunion and so there’s some nostalgia there of, “Aw, remember what we were like when we first met?” That kind of stuff. It’s really nice. I really love that relationship and they’ve stayed true to it. The great thing about this franchise is that, of course, there’s the raunchy humor but here’s also a lot of heart to it. And this fourth movie does not miss the boat on that at all.

Hannigan says that writer-directors Hurwitz and Schlossberg are "big fans of the franchise" and told Hannigan that they have wanted to write a movie like the first American Pie before it was initially released.

[Jon and Hayden] had said that basically they wanted to write [a film like] the original movie and then one of them saw the trailer for it. He called the other and said, “Somebody wrote our movie!” So they’ve been sort of kicking themselves that they missed the boat back in, whenever it was, ’99.

What’s great about what Jon and Hayden have done is they’ve made a really good movie that people who aren’t familiar with the franchise will love, but they’ve also given the people that love the franchise a lot of inside jokes and stuff that you’ll really appreciate if you’re a fan of the American Pies.

Of course, considering the infamous story Hannigan's Michelle shared in the original movie, the question had to be asked: will the flute make an appearance? "You will see the old band room at least," said Hannigan. Fans of the 2005 spin-off American Pie Presents: Band Camp have to be relieved.